1. Field of the Invention
The present invention relates generally to conveyor belts and conveyor chains, and more particularly, but not by way of limitation, to a conveyor belt or conveyor chain having a plurality of nodules formed on an upper side thereof to provide a low friction conveying surface that remains substantially free of debris.
2. Description of Related Art
Many types of products are transported through a plant on a conveyor belt or a conveyor chain during the processing and packaging of the products. To this end, numerous types of conveyor belts and conveyor chains exist for transporting different products and accommodating the specific processing requirements of certain products. For example, flat wire belts are useful for transporting products that must be washed or dried in that water and air are able to pass freely through the wire belt. On the other hand, belts and chains with a continuous conveying surface are often used to transport meat, poultry, and beverage containers.
Particularly, when processing beverages, it is often required that the containers be backed up at certain points along the line. In these instances, the conveyor belt or chain continues to slide under the slower moving or stationary containers. A problem often encountered, however, is that the friction between the bottom of the containers and the conveying surface increases due to an increase in pressure caused by the accumulation of the containers or the gathering of debris on the conveying surface. The increased friction can result in product damage from wear on the product contact surface, deformation of flexible containers, and breakage of rigid containers due to excessive line pressure. In addition, the phenomena of "bridging" or "shingling" on containers is greatly increased with increased line pressure (friction) causing containers to lock together on the line, stopping production until a manual or mechanical unlocking occurs, and sometimes requiring the conveyor to be shut off to prevent damage to the containers.
To decrease the friction between the bottom of the containers and the conveying surface, the use of water, soap, various lubricants, or specially compounded surfactants is common on current designs of conveyor surfaces. These methods are undesirable because of the added cost to the operation and the complication of the proper disposal of the waste liquids. In addition, some container materials such as paper based laminates, and container decorations, such as labels, marking inks, and container attachments, such as instructions booklets, straws, and promotional coupons are damaged by the presence of these substances on the line. As such, most industries prefer that their conveyor systems be operated without lubricants and even without water, in other words "run dry".
To this end, a need has long existed for an improved conveyor apparatus that has a low friction conveying surface which reduces or eliminates the need for the use of soap and water and which provides a stable surface substantially free of debris, while remaining inexpensive to manufacture and operate. It is to such an improved conveyor apparatus that the present invention is directed.